1. Ultrafiltration fouling control Demineralized water backwashing Louis Lagardère April-July 2009

2. Content 1. Introduction (theory) 2. Experiment and Installation of the setup 3. Results 4. Conclusion 5. Recommendation 1/1409-07-2009

3. 1. Introduction (theory) Demi water is better than UF permeate for backwashing (surface water) Difference demi water/ UF permeate Impact of sodium : 2/1409-07-2009

4. 3/1409-07-2009

5. 2. Experiment and installation of the setup Scheme of the setup 4/1409-07-2009

6. Experimental setupSyringe pumps PLC controller Membrane module 5/1409-07-2009

7. Material : - UF membrane : UFC M5 0.8, Norit X-Flow - Pumps : 1 NE1010 pump (backwashing), 1 DUAL-NE1010 (continuous filtration) Filtration protocol : - 1 cycle : 30 s filtration purge (120 or 240 l/(m^2.h)) 15 min filtration (120 or 240 l/(m^2.h)) 1 min backwash purge (2 x filtration flux) 1 min backwash (2 x filtration flux) - 1 experiment : 14 cycles tableau valves Explication cycles 6/1409-07-2009

8. 3.Results Interpretation of the results : 7/1409-07-2009

9. Feed : Sea water (from den Haag and Zeeland) Backwash :demi water and UF permeate Flux : 120 l/(m^2.h) 8/1409-07-2009

10. Feed : Sea water Backwash :demi water and UF permeate Flux : 120 l/(m^2.h) and 240 l/(m^2.h) 9/1409-07-2009

11. Feed : Sea water Backwash :demi water and UF permeate Flux : 240 l/(m^2.h) 10/1409-07-2009

12. Feed : sea water Backwash :demi water and UF permeate Flux :180 l/(m^2.h) 11/1409-07-2009

13. Feed : 2,5 mg/l Alginic acid + 3 mmol NaCl Backwash :demi water and UF permeate Flux :240 l/(m^2.h) 12/1409-07-2009

14. 4. Conclusion For sea water, backwashing with demi water is also more efficient than backwashing with UF permeate The higher the filtration flux is, the more fouling we can observe 13/1409-07-2009

15. 5. Recommendation More experiments should be conducted for alginic acid solution Tap water should be tested to check whether it can replace demi water for sea water application (cheaper) 14/1409-07-2009

16. Ultrafiltration fouling control Demineralized water backwashing